Apparatus for varying the air quantity in air distribution chambers



June 7, 1966 s. w. WALLlN 3,254,830 APPARATUS FOR VARYING THE AIRQUANTITY IN AIR DISTRIBUTION CHAMBERS Filed March 18, 1964 INVENTORI BYSVEN WERNER WALLIN WW ATT Y S,

United States Patent 3,254,830 APPARATUS FOR VARYING THE AIR QUANTITY INAIR DISTRIBUTION CHAMBERS Sven Werner Wallin, Taby, Sweden, assignor toAktie- 'bolaget Svenska Flaktfabriken, Stockholm, Sweden Filed Mar. 18,1964, Ser. No. 353,032

Claims priority, application Sweden, Mar. 19, 1963,

3,008/ 63 2 (Ilaims. (Cl. 230-44) The present invention relates toapparatus forvarying the quantity of gaseous medium in a mediumdistribution chamber for the supply and discharge of air or othergaseous medium. In devices of this kind it is common practice to varythe air quantity by varying the speed of the fans used or by means ofthrottling the fans. Devices for speed control are usually complicated,and the use of pressure regulators is an uneconomical solution in viewof the great power consumed in such devices.

It is an object of the invention to solve the abovementioned problem bysimplemeans, which means is characterized in that the air distributionchamber is equipped with several fans operating in parallel, which fansmay be connected and disconnected individually, and each of which isprovided with self-closing, non-return dampers.

The non-return dampers may in a known manner he made as verticallyoriented damper blades or flaps, the swinging centres of which are sodisplaced with respect to the vertical that a self-closing efiect isautomatically obtained, when the fan associated therewith isswitchedotf. According to a suitable embodiment the damper blades orflaps are inter-connected by a coupling rod secured at differentdistances from the swinging centres of the blades or flaps in such amanner that when in their open position, a diifusor is formed. In plantswith a number of co-operating distributing chambers, these chambers are,according to a suitable embodiment of the invention, mutuallyinterconnected by one or more connecting channels thus creating a commonair distributing system in order to obtain increased flexibility invarying the air quantity.

The invention will now be described in greater detail with reference tothe accompanying drawing, wherein:

FIG. 1 is a profile view of a distribution chamber having a pair ofworking fans, and a portion of which chamber is cutaway to betterillustrate the mounting of the fans in the chamber;

FIG. 1a is a perspective view of a centrifugal fan constructed inaccordance with the invention; and

FIG. 2 is a perspective view of a plurality of co-operating distributionchambers.

In the drawing a distribution chamber 1 is equipped with a plurality offans, in the present instance two designated 2 and 3 comprisingcentrifugal fans having nonreturn dampers 4a, 4b as shown in FIG. 1a.The nonreturn dampers are, according to the invention constructed asvertically oriented damper blades or flaps having swinging centers oraxes 5 and 6, which centers are displaced with respect to the verticalplane so that a self-closing effect is automatically obtained when thefan in question is switched-off. To this end, and as illustrated inFIGS. 1 and 1a the swinging axes 5 and 6,

although substantially vertically oriented, are mounted in the terminalopen end 12 of the fan casing 13 in such a manner that the lowerportions of the axes are offset from the vertical. In the presentinstance oifsetting the axes 5 and 6 from the vertical is accomplishedby connecting the fan casing to the interior of the chamber 1 at anangle to the horizontal. As illustrated in FIG. 1,

the fan is angularly positioned by a spacer 14, located at the lowerportion of the casing 13, and between the interior of the chamber 1 andthe terminal end 12 of the fan 2. A coupling rod 7 is secured at thedamper blades or flaps at different distances from the swinging axes ofthe damper blades or flaps in such a manner that the damper blades orflaps 4a, 4b in their open position, form a diffuser. In a typicalembodiment, a treatment plant 8 comprises four distribution chambers 1a,1b, 1c and 1d located opposite to each other. The distribution chambersare as shown in FIG.'2 mutually inter-connected by means of a number ofconnecting channels 9, which, together with the distribution chamberscreate a common air distributing system. As illustrated the fansconnected to the distribution chambers may be displaced both verticallyand horizontally. The fans located opposite to each other on either sideof the treatment plant are preferably interconnected to be switched-onor switched-01f at the same time. In order to make it possible to cleanthe treatment plants easily, cleaning doors are provided on thedistribution chambers. During this cleaning, in order not to spoil thebalance in the system, which balance is gained thanks to the invention,the cleaning doors located opposite to each other on either side of thetreatment plant should preferably be inter-connected for simultaneousopening.

Although the invention has been described with a certain degree ofparticularity, it is understood that the present disclosure has beenmade only by way of example and that numerous changes in the details ofconstruction and the combination and arrangement of parts may be madewithout departing from the spirit and the scope of the invention ashereinafter claimed.

What is claimed is:

1. Apparatus for varying the quantity of gaseous medium supplied into adistribution chamber, said distribution chamber including a plurality offans operating in parallel, said fans adapted for connection anddisconnection individually and each having at least a pair ofsubstantially vertically oriented dampers mounted in the terminal openend of said fan, each of said dampers having vertically orientedswinging axes, said axes being offset whereby disconnection of at leastone of said fans causes said dampers to substantially close ofi theoutlet of said one fan automatically, thereby impeding reverse flow insaid fan, said dampers being of a fiat configura tion andinter-connected by means of a coupling rod secured to said dampers atdiffering distances from said swing axes wherein said dampers in theiropen position define a flow path of increasing cross-sectional area fromthe swinging axes outwardly, thereby causing the flow of gaseous mediumto expand as it traverses through the dampers.

2. Apparatus in accordance with claim 1 including a plurality ofmutually inter-connected distribution chambers, each of said chambersconnected to the other by means of connecting channels whereby a commonair distribution system is obtained.

References Cited by the Examiner UNITED STATES PATENTS 1,946,300 2/ 1934Vercruyssen 230-114 2,030,993 2/ 1936 Langenkamp et a1. 230-1142,279,425 4/ 1942 Voysey f 230-114 2,673,512 3/1954 Henney 98-102,682,951 7/1954 Hamburg 230-114 MARK NEWMAN, Primary Examiner. W. I.KRAUSS, Assistant Examiner.

1. APPARATUS FOR VARYING THE QUANTITY OF GASEOUS MEDIUM SUPPLIED INTO ADISTRIBUTION CHAMBER, SAID DISTRIBUTION CHAMBER INCLUDING A PLURALITY OFFANS OPERATING IN PARALLEL, SAID FANS ADAPTED FOR CONNECTION ANDDISCONNECTION INDIVIDUALLY AND EACH HAVING AT LEAST A PAIR OFSUBSTANTIALLY VERTICALLY ORIENTED DAMPERS MOUNTED IN THE TERMINAL OPENEND OF SAID FAN, EACH OF SAID DAMPERS HAVING VERTICALLY ORIENTEDSWINGING AXES, SAID AXES BEING OFFSET WHEREBY DISCONNECTION OF AT LEASTONE OF SAID FANS CAUSES SAID DAMPSERS TO SUBSTANTIALLY CLOSE OFF THEOUTLET OF SAID ONE FAN AUTOMATICALLY, THEREBY IMPEDING REVERSE FLOW INSAID FAN, SAID DAMPERS BEING OF A FLAP CONFIGURATION AND INTER-CONNECTEDBY MEANS OF A COUPLING ROD SECURED TO SAID DAMPERS AT DIFFERINGDISTANCES FROM SAID SWING AXES WHEREIN SAID DAMPERS IN THEIR OPENPOSITION DEFINE A FLOW PATH OF INCREASING CROSS-SECTIONAL AREA FROM THESWINGING AXES OUTWARDLY, THEREBY CAUSING THE FLOW OF GASEOUS MEDIUM TOEXPAND AS IT TRAVERSES THROUGH THE DAMPERS.